Distribution characteristics and pollution assessment of heavy metals in the surface sediments in the middle of Haihe river basin

In order to understand the distribution characteristics and pollution status of heavy metals in the surface sediments in the middle of Haihe River Basin, the mass ratios of Cr, Ni, Cu, Zn, As, Cd, Hg and Pb in the surface sediments of 17 sampling sites were determined. The homology, pollution source and pollution degree were analyzed by correlation analysis method, enrichment coefficient method and geoaccumulation index method. The results show that the heavy metal mass ratios in the surface sediments in the middle of Haihe River Basin generally decreased compared with the historical level and the pollution coefficients of eight heavy metals were Cd(1. 98), Hg(1. 80), Cu(1. 37), Zn(1. 18), Pb(1. 12), Ni(1. 07), Cr(1. 02) and As(0. 77) from high to low, wherein Cd pollution was relatively serious; The average enrichment factor values of Cd and Hg were higher than 1. 5 with the pollution source mainly from human input, while the rest six heavy metals were mainly from natural sources. The pollution of heavy metals in the middle of Haihe River Basin was relatively light in general with moderate pollution levels at some sites. © 2021, Editorial Board of Water Resources Protection. All rights reserved.